By their very nature, fluid couplings, which depend for their integrity upon one being threadably torqued into another, are subject to failure because unthreading may occur, particularly in an environment where there is vibration. The problem becomes acute where the fluids being coupled are hazardous or critical equipment failure may occur in the event of a leakage. Both undesirable states may occur where fluid being coupled is an ignitable fuel and the locale is an aircraft or space vehicle.
Currently, and perhaps the best presently known method to lock crucial fluid couplings together, is to secure them with a wire, there typically being openings in portions of mating fittings through which a wire from one to the other may be fastened. The typical problem with this means is that often the wire has too much slack or stretches, so some loosening may occur before positive locking is effected.
Another locking arrangement for locking elements of a conventional two-part fluid coupler is disclosed in U.S. Pat. No. 3,201,149. In this case, the coupling itself is specially constructed wherein a collar nut of one part of the fitting has teeth around an end which mesh with facing teeth on a locking ring of the second part of the fitting. This ring also has teeth around its internal diameter, and these fit over and lock to mating teeth on an outer diameter of a fixed portion of the second part of the fitting. This ring is spring biased to a position where the two sets of teeth are engaged wherein ultimate locking of the two parts of the fitting is effected.
It is the object of this invention to provide a locking assembly which is adapted to lock together elements of existing, standard, fluid couplers and to accomplish this by an assembly which is positive in its locking and yet is relatively simple and inexpensive to manufacture.